| QD | Qi deficiency |
|---|---|
| QYD | Qi and Yin deficiency |
| SAIDS | sexually acquired immunodeficiency syndrome; simian acquired immune deficiency syndrome |
| SAPD | sphingolipid activator protein deficiency |
| SCD | scleroderma; service-connected disability; sickle-cell disease; spinocerebellar degeneration; subacu... |